The Highways Agency unveiled its proposals at a meeting for council representatives and environmentalists at the Chimney House Hotel in Sandbach.

Protesters say that they are disgusted with the plans and claim the government should be investing more money in public transport and measures to reduce the number of cars on the road.

Campaigns co-ordinator for South Cheshire Friends of the Earth Tania Sayer said: 'Tony Blair's government has suspended democracy and replaced it with a 'we know what is best for you, even if we know that it is not what you either need or want' attitude. It would cover the county in tarmac. I am deeply disturbed.

'It has been proven in study after study that more roads lead to more traffic. There is a complete contradiction between a road building programme and Tony Blair's assertions that climate change is the planet's greatest threat.'

Three options were put forward for the 50-mile development between Junctions 11a and 19. They included widening the existing congested M6 either through adding extra lanes on each side, constructing a new four-lane carriageway alongside the existing lanes, or creating a new M6 Expressway toll road that will run parallel to the current motorway.

Lillian Burns, vice-chairman and transport spokeswoman for the Campaign to Protect Rural England's Cheshire branch, said she had fears that large parts of Sandbach would be affected by the development including Sandbach Primary School.

She added: 'Existing M6 junctions 18 at Middlewich, 17 at Sand-bach and 16 at Crewe and Nantwich would have to be rebuilt. The scale of new infrastructure involved, which would include new bridges, viaducts and underpasses, would be huge.'

Highway Agency officials said on Friday that they are only creating concepts for the development and that any decision would have to be taken by government. The agency will hand over its proposals to Transport Secretary Alistair Darling in the spring.

There will then be a period of public consultation which is expected next year before a decision on what option to take on the motorway is made.